Earlier this month, scientists on the project kept extremely hot plasma at a temperature three times that of the sun's core for more than 100 seconds during an experiment at their Hefei research facility. It was almost double the record set by the team last year.
They're aiming to sustain the burn for more than 1,000 seconds – using a ring-shaped device known as a tokamak – at which point the scientists expect the plasma to produce a self-sustainable nuclear chain reaction, an important step for power generation.
That milestone would be less than six years away, based on Song's estimate. "We hope to go into business in 50 to 60 years," he told the newspaper.
At the Experimental Advanced Superconducting Tokamak facility in Anhui province, the chain reaction that takes place in the sun to provide life-giving energy is simulated using plasma – two hydrogen atoms merge into one helium and in the process release a large amount of energy. This extremely hot gas – whose temperature can reach up to 10 times that of the sun's core – is contained by a strong magnetic field to prevent it from coming into direct contact with the inner wall of the reaction chamber. The tokamak fusion device was invented by Soviet physicists in the 1950s.
More from the South China Morning Post:
China one step closer to harnessing clean, limitless energy from nuclear fusion
Scientists used abacuses to develop China's first nuclear submarine
Hong Kong, China most at risk of financial crisis, bank warns
The development of fusion technology – particularly the idea of applying it to nuclear reactors to generate clean energy – has been held back by the difficulty of containing the reaction so that heat is released in a slow and controllable way.
But Song said the Chinese scientists were a step ahead, in part because they could mass-produce some of the world's most advanced superconducting wires that can create a strong magnetic field using a lot less power than others.
Hundreds of tonnes of these wires – which are as fine as hair – are rolled out in Chinese factories every year at a cost of 30,000 yuan (US$4,400) per individual wire.
He said the country could start building "within a few years" a large-scale fusion plant to assess whether it was feasible to generate power.